Method of hot plating containers



Oct. 29, 1935. J, B, DEMERS 2,018,951

METHOD OF HOT PLATING. CONTAINERS Filed June 23, 1934 Patented Oct. 29, 1935 METHOD 01' HOT PLATING CONTAINERS Isaie J. B. Demers, St. Paul, Minn, assignor. to Superior Metal Products Company, St. Paul, Minn, a corporation of Delaware Application June 23, 1934, Serial No. 732,185

. 5 Claims. (Cl. 91-102) This invention relates to a method of hot plating containers and particularly containers of the type used for dairy products wherein considerations of sanitation and durability are of prime importance. I

It is my object to provide 'an improved proce for hot plating the walls and bottoms of containers in one operation.

A particular object is to provide a novel proc- 10 I ass for plating milk cans and the like, which are subject tohard use in handling and shipping, whereby the thickest and most durable plating is obtained on the lower portions of the cans or other containers.

15 Other objects will appear and be more fully pointed out in the following specification and Referring to the accompanying drawing, which illustrates the invention as applied to a milk can;

20 Figure 1 is a part side elevation and part central, vertical section showing the milk can assembled, ready for the 'plating operation;

Fig. 2 is a fragmentary, central, vertical section through the bottom portion of the can, on a somewhat larger scale, after the plating;'

Fig. 3 is a fragmentary section on a still larger scale and showing the closure for the small bottom opening before the plating operation, and

Fig. 4 is a section taken on the line H of i) Fig. 1, illustrating the bottom closure after it has been scaled by the plating material.

In the drawing the numeral 5 indicates the sheet metal, cylindrical wall of the can. To the upper periphery of the wall is welded the breast portion 6 of the can and a bottom I is secured by welding its periphery 8 to the wall 5 at a suitable distance from the bottom edge, as indicated in F188. 1 and 2. The bottom I is somewhat concave internally and at the central or lowest point i in the bottom a small opening 9 is provided for the escape of the excess plating material, as hereinafter described. I prefer to make the opening not larger than about one-fourth of an inch in diameter even for the larger cans of ten gallon capacity. Fitting loosely in the opening 9' is a small rivet-like closure Ill, preferably having a slightly flaring head ii on its upper end and a burr II on its lower end to prevent its accidental displacement during the handling incident to the plating process. The periphery of the closure ll may be roughened, fluted or formed with ribs to leave small apertures through which the excess ofmolten plating material escapes from .the interior of the can.

To tin or hot plate the cans after they have been constructed, as illustrated and described above, they are immersed in a bath of molten tin so that the latter completely covers the inner and outer surfaces. It will be understood that asa preliminary to the tinning, the cans may be thoroughly cleansed in an acid bath, two

or more immersions in the tin areusually required and that oxidation of the hot tin may be prevented by treatment well known in this art. After decanting the greater portion of the excess 10 of molten tin, the hot freshly tinned can is then stood in upright position with the opening 9 at the lowest point of the bottom while the remaining excess-of plating material flows down over the inner surfaces of the can and out through the minute apertures around the closure I0 until the plating material has solidified.

During this cooling and draining step of the process, because of the upright position of the can, the plating material is distributed uniformly around the periphery of the can and as the cooling progresses the excess from the upper portion of the can flows down in such a manner as to result in increased thickness of plating l3 on the surfaces of the lower portions of the can when the plating has solidified (Fig. 2). The last of the excess flows into the opening 9 and solidifies around the closure Hi to seal the minute apertures M around the closure, as indicated in Fig. 4. The roughening or grooving of the closure I 0 merely centers it and a smooth, loose fitting closure has been found to function eiilciently. Further, in some cases, I have found it unnecessary to employ a closure and by providing one or more openings 9 approximately oneeighth of an inch in diameter the plating material is caused to seal the opening or openings automatically upon cooling. In either case, the openings are efliciently and neatly sealed without a separate operation. By retaining the can in upright position during the cooling and solidifying of the plating, I also obtain smooth joints and eliminate unsanitary recesses at the junction of the breast 6 with the walls 5 and also at the junction of the bottom I with the walls 5. The 46 resulting container is unusually sanitary and readily cleanable.

' Heretofore in the tinning of one piece and all-welded cansf they have been listed or" tilted with the top of the can down during the solidification of the tin, causing reduced thickness or a scarcity of the tin at the bottom where relatively heavy or thick tinning is desirable and an unequal distribution of tin around the periphery. My invention may be employed to advantage in w v the construction of numerous containers in addition to milk cans such, for example, as ice cream cans and cheese cans. Containers of this class have distinct advantages when constructed without the use of soldered interior joints, because of than solder, completely covers'alljoints.

In my improved process the bottom of the container, having the small drainage opening, is secured to the walls of the container before the tinning operation so that the walls and the bottom may be tinned in one operation and subsequent soldering of the bottom to the walls is avoided.

Having described my invention, what I claim' as new and desire to protect by Letters Patent is:

1. The method of hot plating a container which consists in forming in the bottom of said container a minute perforation, then hot plating said container and placing it in such position as to permit the escape of the liquid contents by gravity through said perforation and allowing the container to cool while permitting the excess of plating material to escape through said perforation, said perforation being sealed merely by the cooling of the plating material therein.

a. The method of hot plating a container having a bottom formed with an outlet opening therethrough adapted to permit the escape of the liquid contents by gravity which consists in hot platingsaid container, then placing it with said opening at the lowest point of the bottom and allowing the container to cool while permitting the excess of plating material to escape through said opening, the size and shape said opening ting the excess of plating material, to escape through said opening and finally sealing said closure in said opening.

4. The method of hot plating ,a container hav-- ing a bottom formed with an opening and said opening having a closure fitting loosely therein,

which consists in hot plating said container, then placing it in such position as to permit the escape of the liquid contents by gravity and allowing the container to cool while permitting the excess of plating material to escape through said opening and finally sealing said closure in said opening merely by the cooling of the plating material on said bottom and closure.

5. The method of hot plating a container for dairy products to efiect progressively increasing thickness of plating material toward the bottom 01 the container, which consists in securing to the walls of the container an internally concave bottom having an opening therein, then hot plating said container, placing it in such position as to permit the escape of the liquid contents by gravity and finally allowing it to, cool while permitting the excess of plating material to escape through said opening, the size and proportion of said opening being such as to cause the sealing of the same merely upon the cooling of said plating material.

rsair: J. B. DEMERS. 

